WASHINGTON — Murrey Marder, a Washington Post reporter whose tenacious coverage of Joseph McCarthy’s anti-communist crusade foreshadowed the senator’s downfall and disgrace, died March 11 at a hospice. He was 93.

The cause was complications from a stroke last month, said his nephew Steve Marder.

Mr. Marder’s career spanned several decades, including World War II service in the South Pacific as a Marine Corps combat correspondent. He joined The Washington Post in 1946 and distinguished himself on the so-called ‘‘Red Beat,’’ the sensational trials and hearings about the alleged communist infiltration of government, Hollywood, and other industries.

In his journalism history book ‘‘The Powers That Be,’’ author David Halberstam described Mr. Marder as ‘‘the perfect choice for the assignment, quiet, intelligent, dogged, and meticulous. There was nothing flashy about a Marder story, no one ever accused him of deft or imaginative prose, but he was above all else careful and fair.’’

Mr. Marder was among a cadre of journalists — including Anthony Lewis of the old Washington Daily News and Philip Potter of the Baltimore Sun — who shunned a stenographic approach to reporting on McCarthy’s charges of spy rings and rampant security threats.

In Halberstam’s account, Mr. Marder spent long hours at the office, agonizing over his stories to add nuance and perspective — often testing the patience of editors who wanted shorter, punchier articles. Not entirely a compliment, future Post executive editor Benjamin Bradlee once described Mr. Marder as ‘‘one of the world’s most thorough reporters.’’

To Mr. Marder, the stakes were too high to work any faster. As he and other journalists would later reveal McCarthy, a Wisconsin Republican, ruined lives and careers through threat and innuendo.

Mr. Marder’s biggest story came in the autumn of 1953, when McCarthy held closed-door hearings into an alleged spy ring at the Army Signal Corps laboratories at Fort Monmouth, N.J. As many as 42 people were suspended without pay. Many of them did not know the precise nature of the charges brought against them.

Mr. Marder spent a week at Fort Monmouth and learned that a vast majority of the security cases had already been investigated and dismissed by the Army. In an interview years later, Mr. Marder described the accusations as ‘‘even flimsier than most — reading the Daily Worker or [knowing] somebody who had gone to school with somebody else who was thought to be a communist.’’

He called the charges the ‘‘dregs’’ of the security investigations from that era but noted that McCarthy ‘‘had built the thing so highly that it was sort of waiting for someone to come along and look at it. And nobody wanted to bother.’’

Mr. Marder laid out his findings in a four articles in early November 1953. Soon afterward, he pressed Army Secretary Robert Stevens to admit there was no evidence of espionage at Fort Monmouth.

The Fort Monmouth episode was one of several attempts by the senator to target armed forces personnel for supposed communist leanings. It was a harbinger of McCarthy’s political demise in 1954 in a nationally televised showdown known as the Army-McCarthy hearings. The senator drew almost unanimously critical coverage and, that December, was censured by the Senate. He died three years later.

In 1957, Mr. Marder opened The Post’s first foreign bureau, in London, and roamed the world as chief diplomatic correspondent. He participated in coverage of the disputed Tonkin Gulf clash between US and North Vietnamese sea forces in 1964 that led President Lyndon B. Johnson to commit US ground forces to the Vietnam War effort.

In 1971, Mr. Marder was one of the chief Post reporters assigned to write stories based on the Defense Department’s secret multi-volume history of the Vietnam War, known as the Pentagon Papers. He was brought into discussions among Post publisher Katharine Graham and top editors about whether to publish the papers at all.

‘‘If The Post doesn’t publish, it will be in a much worse shape as an institution than if it does,’’ Marder had argued, as quoted in Graham’s memoir. He said the paper’s ‘‘credibility would be destroyed journalistically for being gutless.’’

The Nixon administration tried to prevent The New York Times and The Post from printing the documents, but the Supreme Court ruled in the newspapers’ favor, citing First Amendment rights.

His wife, the former Frances Sokoloski, died in 1996. As a widower with no immediate survivors, he used $1.3 million of his Post stock — a vast portion of his retirement savings — to start a public watchdog program affiliated with Harvard University’s Nieman Foundation for Journalism.